Coronal balance with circumferential minimally invasive spinal deformity surgery for the treatment of degenerative scoliosis

J Neurosurg Spine 34:879–887, 2021

Coronal malalignment (CM) in adult spinal deformity is associated with poor outcomes and remains underappreciated in the literature. Recent attempts at classifying CM indicate that some coronal shifts may be more difficult to treat than others. To date, outcomes for circumferential minimally invasive surgery (cMIS) of the spine in the context of these new CM classifications are unreported.

METHODS A retrospective evaluation of patients with degenerative scoliosis (Cobb angle > 20 ) consecutively treated with cMIS at a single institution was performed. Preoperative and 1-year postoperative standing radiographs were used to make the comparisons. Clinical outcome measures were compared. Patients were subgrouped according to the preoperative distance between their C7 plumb line and central sacral vertical line (C7-CSVL) as either coronally aligned (type A, C7-CSVL < 3 cm); shifted ≥ 3 cm toward the concavity (type B); or shifted ≥ 3 cm toward the convexity (type C) of the main lumbar curve.

RESULTS Forty-two patients were included (mean age 67.7 years). Twenty-six patients (62%) were classified as type A, 5 patients (12%) as type B, and 11 patients (26%) as type C. An average of 4.9 segments were treated. No type A patients developed postoperative CM. All type B patients had CM correction. Six of the 11 type C patients had CM after surgery. Overall, there was an improvement in the C7-CSVL (from 2.4 to 1.8 cm, p = 0.04). Among subgroups, only type B patients improved (from 4.5 to 0.8 cm, p = 0.002); no difference was seen for type A patients (from 1.2 to 1.4 cm, p = 0.32) or type C patients (from 4.3 to 3.1 cm, p = 0.11). Comparing type C patients with postoperative CM versus those without postoperative CM, patients with CM had worse visual analog scale back scores at 1 year (5 vs 1, p = 0.01). Moreover, they had higher postoperative L4 tilt angles (11  vs 5 , p = 0.01), indicating inadequate correction of the lumbosacral fractional curve.

CONCLUSIONS cMIS improved coronal alignment, curve magnitudes, and clinical outcomes among patients with degenerative scoliosis. It did not result in CM in type A patients and was successful at improving the C7-CSVL in type B patients. Type C patients remain the most difficult to treat coronally, with worse visual analog scale back pain scores in those with postoperative CM. Regional coronal restoration of the lumbosacral fracture curve should be the focus of correction in cMIS for these patients.

 

Surgical correction of severe adult lumbar scoliosis (major curves ≥ 75°): retrospective analysis with minimum 2-year follow-up

J Neurosurg Spine 31:548–561, 2019

Prior reports have demonstrated the efficacy of surgical correction for adult lumbar scoliosis. Many of these reports focused on mild to moderate scoliosis. The authors’ objective was to report their experience and to assess outcomes and complications after deformity correction for severe adult scoliosis.

METHODS The authors retrospectively analyzed consecutive adult scoliosis patients with major thoracolumbar/lumbar (TL/L) curves ≥ 75° who underwent deformity correction at their institution. Those eligible with a minimum 2 years of follow-up were included. Demographic, surgical, coronal and sagittal plane radiographic measurements, and healthrelated quality of life (HRQL) scores were analyzed.

RESULTS Among 26 potentially eligible patients, 22 (85%) had a minimum 2 years of follow-up (range 24–89 months) and were included in the study (mean age 57 ± 11 years; 91% women). The cohort comprised 16 (73%), 4 (18%), and 2 (9%) patients with adult idiopathic scoliosis, de novo degenerative scoliosis, and iatrogenic scoliosis, respectively. The surgical approach was posterior-only and multistage anterior-posterior in 18 (82%) and 4 (18%) patients, respectively. Three-column osteotomy was performed in 5 (23%) patients. Transforaminal and anterior lumbar interbody fusion were performed in 14 (64%) and 4 (18%) patients, respectively. All patients had sacropelvic fixation with uppermost instrumented vertebra in the lower thoracic spine (46% [10/22]) versus upper thoracic spine (55% [12/22]). The mean fusion length was 14 ± 3 levels. Preoperative major TL/L and lumbosacral fractional (L4–S1) curves were corrected from 83° ± 8° to 28° ± 13° (p < 0.001) and 34° ± 8° to 13° ± 6° (p < 0.001), respectively. Global coronal and sagittal balance significantly improved from 5 ± 4 cm to 1 ± 1 cm (p = 0.001) and 9 ± 8 cm to 2 ± 3 cm (p < 0.001), respectively. Pelvic tilt significantly improved from 33° ± 9° to 23° ± 10° (p < 0.001). Significant improvement in HRQL measures included the following: Scoliosis Research Society (SRS) pain score (p = 0.009), SRS appearance score (p = 0.004), and SF-12/ SF-36 physical component summary (PCS) score (p = 0.026). Transient and persistent neurological deficits occurred in 8 (36%) and 2 (9%) patients, respectively. Rod fracture/pseudarthrosis occurred in 6 (27%) patients (supplemental rods were utilized more recently in 23%). Revisions were performed in 7 (32%) patients.

CONCLUSIONS In this single-center surgical series for severe adult scoliosis (major curves ≥ 75°), a posterior-only or multistage anterior-posterior approach provided major curve correction of 66% and significant improvements in global coronal and sagittal spinopelvic alignment. Significant improvements were also demonstrated in HRQL measures (SRS pain, SRS appearance, and SF-12/SF-36 PCS). Complications and revisions were comparable to those of other reports involving less severe scoliosis. The results of this study warrant future prospective multicenter studies to further delineate outcomes and complication risks for severe adult scoliosis correction.

A Prospective, Nonrandomized, Multicenter Evaluation of Extreme Lateral Interbody Fusion for the Treatment of Adult Degenerative Scoliosis

Spine 2010;35: S322–S330

Study Design. Prospective multicenter nonrandomized institutional review board-approved observational study of clinical and radiographic outcomes of the extreme lateral interbody fusion (XLIF) procedure in adult scoliosis.

Objective. Perioperative measures from this longitudinal study were compiled to identify the short-term results and complications of the procedure.

Summary of Background Data. The surgical treatment of adult scoliosis presents a treatment challenge. Neural decompression with combined anterior/posterior instrumented fusion is often performed. These procedures have been reported to carry a high risk of complication, particularly in the elderly patient population. Over the past decade, less invasive surgical approaches to neural decompression and fusion have been popularized and have recently been applied in the treatment of degenerative scoliosis. To date, there has been little published data evaluating these treatment approaches.

Methods. A total of 107 patients who underwent the XLIF procedure with or without supplemental posterior fusion for the treatment of degenerative scoliosis were prospectively studied. Intraoperative data collection included surgical procedural details, operative time, estimated blood loss, and surgical complications. Postoperative complications, length of hospital stay, and neurologic status were recorded. For this report, perioperative data (inclusive of outcomes through the 6-week postoperative clinic visit) were evaluated.

Results. In all, 107 patients (mean age, 68 years; range, 45–87) were treated with XLIF; 28% had at least 1 comorbidity. A mean of 4.4 levels (range, 1–9) were treated per patient. Supplemental pedicle screw fixation was used in 75.7% of patients, 5.6% had lateral fixation, and 18.7% had stand-alone XLIF. Mean operative time and blood loss were 178 minutes (58 minutes/level) and 50 to 100 mL. Mean hospital stay was 2.9 days (unstaged), 8.1 day (staged, 16.5%), 3.8 days overall. Five patients (4.7%) received a transfusion, 3 (2.8%) required intensive care unit admission, and 1 (0.9%) required rehabilitation services. Major complications occurred in 13 patients (12.1%): 2 (1.9%) medical, 12 (11.2%) surgical. Of procedures that involved only less invasive techniques (XLIF stand-alone or with percutaneous instrumentation), 9.0% had one or more major complications. In those with supplemental open posterior instrumentation, 20.7% had one or more major complication. Early reoperations (3) (all for deep wound infections) were associated with open posterior instrumentation procedures.

Conclusion. The morbidity in adult scoliosis surgery is minimized with less invasive techniques. The rate of major complications in this study (12.1%) compares favorably to that reported from other studies of surgery for degenerative deformity.

Less Invasive Surgical Correction of Adult Degenerative Scoliosis. Part II: Complications and Clinical Outcome

Neurosurgery 67:1609–1621, 2010 DOI: 10.1227/NEU.0b013e3181f918cf

Surgical correction of adult degenerative scoliosis is a technically demanding procedure with a considerable complication rate. Extensive blood loss has been identified as a significant factor linked to unfavorable outcome.

OBJECTIVE: To report on the complication profile and clinical outcomes obtained with less invasive image-guided surgical correction of degenerative (de novo) scoliosis in a high-risk population.

METHODS: Thirty patients (age, 64-88 years) with progressive postural impairment, back pain, radiculopathy, and neurogenic claudication caused by degenerative scoliosis were treated by less invasive image-guided correction (3-8 segments) by multisegmental transforaminal lumbar interbody fusion and facet fusions. With a mean follow-up of 19.6 months, intraoperative blood loss, curve correction, fusion and complication rates, duration of hospitalization, incidence of hardware-related problems, and clinical outcome parameters were assessed using multivariate analysis.

RESULTS: Satisfactory multiplanar correction was obtained in all patients. Mean intraoperative blood loss was 771.7±231.9 mL, time to full ambulation was 0.8 ± 0.6 days, and length of stay was 8.2 ± 2.9 days. After 12 months, preoperative SF12v2 physical component summary scores (20.2 ± 2.6), visual analog scale scores (7.5 ± 0.8), and Oswestry disability index (57.2 ± 6.9) improved to 34.6 ± 3.9, 2.63 ± 0.6, and 24.8 ± 7.1, respectively. The rate of major and minor complications was 23.4% and 59.9%, respectively. Ninety percent of patients rated treatment success as excellent, good, or fair.

CONCLUSION: Less invasive image-guided correction of degenerative scoliosis in elderly patients with significant comorbidity yields a favorable complication profile. Significant improvements in spinal balance, pain, and functional scores mirrored expedited ambulation and early resumption of daily activities. Less invasive techniques appear suitable to reduce periprocedural morbidity, especially in elderly patients and individuals with significant medical risk factors.